Tunnel barrier to spin filter: Electronic-transport characteristics of transition metal atom encapsulated in a small Cadmium Telluride cage.

First-principles theory-based comparative electronic-transport studies were performed for an atomic chain of Au, a bare CdTe cage-like cluster, and a single transition metal (TM) (Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ru, Rh, Pd) atom encapsulated within the CdTe using Au(111) as the electrodes. The bare cluster was semiconducting and acted as a tunnel barrier up to a particular applied bias and then beyond that the device displayed a linear current-voltage relationship. Several TMs (Ti, V, Cr, Mn, Fe) encapsulated in the cage showed a half-metallic behavior and spin-filtering effect in the characteristics of the device.